Summary: INTRODUCTION
Satellites contain onboard equipment for sens-
ing Earth and space, and communications links
that transmit the data back to Earth for pro-
cessing. Depending on altitude and movement,
satellites are classified into three types: geosyn-
chronous Earth orbit (GEO), medium Earth
orbit (MEO), and low Earth orbit (LEO). LEO
satellites have several advantages, such as low
propagation delay and low power requirement
over GEO/ MEO satellites. The advantages
make LEO satellite constellations very suitable
for ubiquitous access and enable seamless
mobility on Earth. In the case of LEO satel-
lites, data are downloaded when a satellite
comes in contact with a ground station and are
stored on a computer for further processing.
Future satellite systems will consist of IP-
enabled equipment that will allow direct down-
load of data from the satellites by IP-based